ii. l. )oints (articulating bones) are enclosed within a

fibrous capsule.2. The synovial fluid separates articulatlng bones

(b) Vertebrae are linked together by ligaments to forman upright column and they allow the attachment ofmuscles

(c) i. 81ii. The femur has to bear all the weight of the upper

bodY.

iii. Sunlight2 (a) i. P: Biceps

Q: Tricepsii. P: Flexor

Q: Extensor(b) A muscle can only pull and cannot push. Therefore, the

coordinated contraction and relaxation of antagonisticmuscles can pull a bone in opposite directions andmake movement possible.

(c) i. R: TendonS: Ligament

ii. R: Attaches a muscle to a boneS: Binds two bones together

iii. R needs to pull bones so it should not be stretchable.S is flexible to enable bones to move at the joint.

3 (a) R: ParenchymaS: Xylem

(b) X: TerrestrialY: Aquatic

(c) X: Has more xylem tissue to provide support againstbending stress produced by wind.

Y Has large and numerous intercellular space toprovide water buoyancy.

(d) R: The water content of the thin-walled parenchymacells provide turgid support.

S: The rigidity of the thickened cell wall/xylem providesmechanical support.

Section Ba (a) . To search for food, mate and shelter [1 m)

. To escape from predators and other dangers [1 m)(b) Grasshopper - walking

. Uses the first two pairs of smaller legs to walk [1 z]

. To walk - supports body by using three legs; theother three legs move the body forward ll ml

Grasshopper - jumping. A pair of long hind legs for jumping ll ml. Flexor muscles in the femur contract and bring the

tibia close to the femur in a "Z" position. l1 ml. Then the extensor muscle contracts and propels the

grasshopper into the air.Grasshopper - flyrng. Has a pair of wings; movements of the wings drive

air downwards and produce lift and flight. [1 m]. Contractions of the flight muscles move the wings

forward and backwards, upwards and downwards.

[1 m]Fish - swimming. There are myotomes on both sides of its vertebra

column. [1 m]. Antagonistic contractions of myotomes create wave-

like movements from the anterior to the tail. [1 z]. Wave-like movements push water backvrards and its

11 m\

bodv forward. [1 m]

The grasshopper needsto support its bodyweight in air against thegravitational pull.It has a strong chitinousexoskeleton to supportits body and protectits internal organs, andstrong legs to carry itsbody.

12 ml

The body weight of thefish is supported bywater buoyancy.It only requires aninternal bony skeletonto support its body forswimming.

12 ml

Resistance to movementby the air moleculesvery low due to thelow density of theatmosphere.The grasshopper movesabout easily by walking,hopping, and flyingwithout the need for a

streamlined body.

12 n)

The high density ofwater creates a lot ofresistance and drag tomovement.The body ofa fish isstreamlined to reducewater resistancewhile fins help it tomanoeuwe and swim inwater.

[2 m]

5 (a) i. . The human musculoskeletal system is an organsystem that gives humans the abiiity to move byusing the muscular and skeietal systems. [2 m]

. It is made up of the skeleton, muscles, cartilage,tendons, ligaments, joints and other connectivetissues. [2 m]

ii. . Support - as a framework for tissues and organsto attach themselves to as well as holding thebody above the ground. ll ml

. Locomotion - antagonistic pairs of muscles workto flex and extend the legs during walking andrunning. ll ml

. Movement - e.g. contractions of external andinternal intercostal muscies move the ribcage,enabiing inhalation and exhalation to occur.

[1m). Protection - skull protects the soft and delicate

brain. 11 ml. Production of blood cells - the red marrow

of some bones produces blood cells to replaceexisting cells that have been destroyed by theliver. lr ml

. Storage - calcium and phosphorus are storedin bones; muscle proteins, are converted intosugar for respiration when there is a shortage ofglycogen and fat. [1 m)

(c)

(b) i.

ii

Posture - the correct way the human body shouldbe carried against gravity while standing, sitting orlving down. [2 m]. To keep the bones and joints in the correct

alignment so that the muscles can functionproperly Uml

. To prevent fatigue and strain by using musclesmore efficiently lr ml

. To prer-ent strain or overuse of certain parts ofthe musculoskeletal system [1 m]

. To prelent backache and muscular pain due to

strain, overuse or abuse of the musculoskeletalsystem 11 ml

. To avoid and decrease the abnormal wearing ofjoint surfaces that could resuit in arthritis [1 la]

. To prevent the vertebral column from becomingfixed in abnormal positions fr m]

. To reduce the stress on the ligaments holding thejoints ofthe vertebral column together 11 ml

. To contribute to a good physical appearance

lt mlDiagram (A) is a herbaceous plant or herb; hasrelatively little woody tissue and no lasting woodyshoots. 12 mlVascular bundles: Arranged in a ring around toprovide flexibility and support.

6(a).

phosphorus

CHAPTER 3: Coordination and ResponsePAPER T

lC 2B7B 8C

t3B 14B19c 20c25C 26A3rC 32837C

lr m)Parenchyma: Forms most of the herbaceous plant;are living cells with thin cellulose walls; contributeto support via turgidity. 11 mlCollenchyma: Found just below the epidermis instems and petioles; forms a cylinder of flexible butstrong tissue (cellulose strands) which allows themto bend in the wind lr ml

. Diagram (B) is a woody plant; has shoots that lastyear after year during which time the stems becomehard and woodv. [2 ml

. Sclerenchyma: Dead cells with very thick lignifiedwalls, which provide hard structural support to theplant. lt ml

. Xylem vessels form long cyiindrical vessels, with wallsthickened by lignin, which give the plant support.

. Tracheids consist of dead cells with thick, trrll#lwalls; give support to the plant ll ml

(b) Support in plants:. To grow towards sunlight so that photosynthesis can

take place lt ml. To support tropic (besides phototropic) and nastic

responses ll ml. To position leaves for maximum absorption of light

lor maximum photosynthesis lr ml. To produce and display flowers to attract insects for

pollination [1 m1. To hold fruits up for effect dispersal ofseeds [l m]Support in animals:. To maintain the body shape ll ml. Supporting tissues provide protection for the delicate

tissues and internal organs. lt ml. To allow movement - supporting tissues form a hard

skeleton against which the muscles can act lI m]. To escape from predators or to capture prey [1 m]. To enable breathing and act as a store for calcium and

[1ml

3B9A

1sC2tA27833D

4C 5B10D rrAt6D t7D22D 23D284 29C34D 358

6Bt2A18B24C30B36A